a) Field of the Invention PA1 b) Prior-art Statement
The present invention relates to a rearview mirror system for vehicles, and more specifically to a rearview mirror system of which the mirror housing is to be installed on either side of a car body, for example, and can be turned by hand or as driven by a motor to a viewing position (normal position) where it protrudes laterally from the car body and gives the car driver a rearview and to a viewing position (folded position) where the mirror housing is nearly parallel to the car body.
Various rearview mirrors of this type have been proposed so far, including a typical one disclosed in the Japanese Unexamined Patent Publication No. Sho-61-94845 (laid open on May 13, 1986). In this conventional door mirror, the mirror housing having a mirror assembled therein is adapted to take three positions: Viewing, first and second parking positions. Namely, when in the viewing position, the mirror housing protrudes laterally from the car body and gives the car driver a rearview. When in the first parking position, the mirror housing outer end is directed toward the tail of the car body while the housing mirror side faces the lateral side of car body. When in the second parking position, the mirror housing outer end is directed toward the head of the car body while the housing rear side faces the lateral side of car body. The mirror housing can be turned from the second parking or viewing position to the first parking position or from the first parking position to the viewing or second parking position, depending upon the direction in which it is pressed by hand, body of a person or any other thing. The mirror housing can also be turned as pressed by hand. This rearview mirror has a positioning unit to turn the mirror housing in the above-mentioned directions. The positioning unit has a stationary member that is to be fixed to a base, and a rotary member that is to be fixed to the mirror housing. A shaft is provided in the stationary member and the rotary member is rotatably mounted on the shaft. The rotary member is forced by a coil spring fitted on the shaft to the stationary member. When the mirror housing is pressed by hand, the rotary member can be rotated along with the mirror housing to the viewing or first parking position against the pressure of the coil spring.
Also, another rearview mirror of the above-mentioned type in which the mirror housing is turned as driven by a motor is disclosed in the Japanese Unexamined Utility Model Publication No. Sho-4-114839 (laid open on Oct. 9, 1992). In this example, the positioning unit comprises a shaft on a stationary member, a gear mounted on the shaft, a clutch disposed between the gear and shaft, a motor on a rotary member and a gear train including a gear rotating on its own axis and about the gear on the shaft while being in mesh with the gear on the shaft. When the motor drives the gear train, the gear of the gear train that is in mesh with the gear on the shaft rotates on its own axis and about the gear on the shaft to turn the rotary member about the shaft to the viewing or first parking position. When the mirror housing is pressed by hand while the motor is being stopped, the clutch is released so that the gear on the shaft is rotated along with the rotary member that thus is turned about the shaft to the viewing or first parking position. When a person or any thing touches or hits the mirror housing in the viewing position, the clutch is released so that the rotary member can be turned about the shaft to the first or second parking position.
In these rearview mirrors, as the mirror housing is turned to the viewing position, balls held in the rotary member move and abut the ends of sector recesses formed in the stationary member concentrically with the rotary shaft of the mirror housing to set the rotary member precisely in the viewing position. Also, when a person or any thing touches or hits the mirror housing in the viewing position, a projection provided as extended from the stationary member to the rotary member enters into a concavity formed in the rotary member to limit a further or full turn of the mirror housing toward the first or second parking position.
As mentioned above, the conventional rearview mirrors use the positioning units in which the mirror housing is turned as driven by a motor and ones in which the mirror housing is to be turned by hand. To turn the mirror housing in case a pair of such rearview mirrors are installed on the body of a car, for example, four positioning units are required, including a positioning unit built in the left-hand mirror in which the mirror housing is turned as driven by a motor, a positioning unit built in the right-hand mirror in which the mirror housing is turned as driven by a motor, a positioning unit built in the left-hand mirror in which the mirror housing is to be turned by hand, and a positioning unit built in the right-hand mirror in which the mirror housing is to be turned by hand. Further, the mirror housing and base are designed in various shapes correspondingly to a variety of car body styles. Since the internal space of the mirror housing varies from one to another mirror housing, the motor-driven positioning unit and manual positioning unit are prepared for each set of the base and mirror housing, thus resulting in a rather large number of positioning unit types. For manufacture of the positioning units, it is not only necessary to prepare, check and manage many molding dies and jigs but also to manage many types of manufactured parts and many finished positioning units. Namely, the manufacture of the rearview mirrors needs large costs.